/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.beans.factory.config;

import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

/**
 * Context object for evaluating an expression within a bean definition.
 *
 * @author Juergen Hoeller
 * @since 3.0
 */
public class BeanExpressionContext {

    private final ConfigurableBeanFactory beanFactory;

    @Nullable
    private final Scope scope;


    public BeanExpressionContext(ConfigurableBeanFactory beanFactory, @Nullable Scope scope) {
        Assert.notNull(beanFactory, "BeanFactory must not be null");
        this.beanFactory = beanFactory;
        this.scope = scope;
    }

    public final ConfigurableBeanFactory getBeanFactory() {
        return this.beanFactory;
    }

    @Nullable
    public final Scope getScope() {
        return this.scope;
    }


    public boolean containsObject(String key) {
        return (this.beanFactory.containsBean(key) ||
                (this.scope != null && this.scope.resolveContextualObject(key) != null));
    }

    @Nullable
    public Object getObject(String key) {
        if (this.beanFactory.containsBean(key)) {
            return this.beanFactory.getBean(key);
        } else if (this.scope != null) {
            return this.scope.resolveContextualObject(key);
        } else {
            return null;
        }
    }


    @Override
    public boolean equals(Object other) {
        if (this == other) {
            return true;
        }
        if (!(other instanceof BeanExpressionContext)) {
            return false;
        }
        BeanExpressionContext otherContext = (BeanExpressionContext) other;
        return (this.beanFactory == otherContext.beanFactory && this.scope == otherContext.scope);
    }

    @Override
    public int hashCode() {
        return this.beanFactory.hashCode();
    }

}
